Thursday 15 March 2012 14.28 EDT
First published on Thursday 15 March 2012 14.28 EDT

Warren Gatland has not been averse to using the roof at the Millennium Stadium as a weapon and he has used France's request that it be open to the expected rain on Saturday to predict Les Bleus will look to deny their hosts a grand slam by playing ugly rugby.

Gatland refused a request by Australia in the autumn of 2010 to close the roof with Wales then struggling with injuries behind the scrum, but his general preference has been for it to be closed. When he learned that his France opposite number, Philippe Saint-André, had turned down Wales's request for the match to be played under cover he, as it were, hit the roof.

"France have picked an old, tough forward pack," said Gatland, who has made one change to the side that beat Italy last Saturday with the captain, Sam Warburton, having recovered from a knee injury. "They have asked for the roof to be open so it is not going to be a pretty game from their point of view, but raw. I expect them to be more physical than open given their selection."

Gatland said he had wearied of the question of whether the roof in Cardiff should be open or shut. Under Six Nations regulations, both sides have to agree for the roof to be closed. Wales will have to expose the pitch to the elements at least three hours before the 2.45pm kick-off on Saturday. "Philippe is being pragmatic with the roof," said Gatland. "He wants to get a win. I have coached against him in the past in the Premiership and he is conservative in the way he approaches the game. I do not think he cares too much about the type of rugby they play. Maybe as a Welsh union we need to make some representations to the International Rugby Board. It is our stadium and as we have the ability to open and close the roof, perhaps we should be the team that decides that. We all have a responsibility to the broadcasters and the public and the game as a whole to make the game as attractive as possible. I hope that it is not closed on Friday night and then it breaks down and we can't open it."

Wales have the opportunity to win their third grand slam in eight seasons, equalling the feat of the 1970s, and it was in that decade that the men in red last went through a championship campaign with the same back division, 1977. Gatland said a clean sweep this year would give him more satisfaction as a coach than in 2008, when he had just taken charge. "All this has come from the last eight months and the build-up to the World Cup," he said. "It has created momentum. What we are excited about is that we can build on this over the next couple of seasons. It is tough winning a grand slam and you need a bit of luck."

Warburton has only played three halves in the Six Nations so far and it will be his third appearance against France. "I have not lasted 20 minutes in the other two," he said, referring to last October's World Cup semi-final, when he was sent off for tip-tackling the wing Vincent Clerc, and last year's championship match in Paris, when he was injured in the opening quarter. "I hope to last a bit longer this time."

Warburton said he had not dwelt on the semi-final and it made no difference to him that Clerc was not playing. "It will be the biggest game of my career and it cannot come soon enough," he said. "I want to measure myself against Thierry Dusautoir. I have become a target, with cheap shots coming in matches from left, right and centre. Perhaps it is a compliment, but I do not mind.

"I am a wing forward because I like physicality and confrontation. I played on the wing when I was young but I did not get involved enough. France have picked a physical pack: happy days."